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Chapter 5: Circadian Rhythm Sleep Disorders

What is Delayed Sleep Phase Disorder?

With Delayed Sleep Phase disorder (DSPD), the individual’s preferred sleep time is delayed three to six hours, compared to conventional times. DSPD is characterized by an inability to fall asleep at a desired, conventional clock time and awaken at a socially acceptable morning time. An alternative name for the disorder is: “circadian rhythm sleep disorder, delayed sleep phase type.”

When allowed to choose their preferred sleep schedule, patients with DSPD exhibit sleep of normal quality and duration for their age and maintain a stable (but delayed) relationship of entrainment to the 24-hour, sleep-wake pattern.1 2 3